<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>常用值</title>
    <style>
        h1{
            color: red;
            color: rgb(255,0,0);
            color: rgb(0,255,0);
            color: #ff0000;
            color: #f00;
            color: #000000;
            color: #000;
            color: #ffffff;
            color: #fff;
            color: rgba(255,0,0,1);
            color: rgba(255,0,0,0.8);
            color: rgba(255,0,0,0.3);
            color: rgba(255,0,0,0.1);
            color: rgba(255,0,0,0);

        }
        .d1{
            background-image: url(img/mr.png) ;
            width: 50px;
            height: 100px;
            background-size: 50px 100px;
            background-color: aqua;

        }
        .d2{
            width: 300px;
            height: 300px;

            background-image: url(img/mr.png);
            border: solid red 5px;
            background-repeat: no-repeat;
            background-position: 125px -50px;
            background-position: 100px 100px;
            background-position: center center;
            background-position: center ;
            background-position: 50% 50%;
            background-position: 100% 100%;
        }
        .d4{
            border: solid red 5px;
            width: 611px;
            height: 376px;
            background-size: 318px 319px;
            background-position: 90% 60%;
            background-repeat: no-repeat;
            background-image: url(img/computer1.png);
            background-color: #e8e8e8   ;
        }


    </style>
</head>
<body>
<h1>测试颜色</h1>
<div class="d1"></div>
<div class="d2"></div>
<div class="d3"></div>
    <div class="text">
        <h1>我是标题</h1>
    </div>
<div class="d4">

</div>
</body>
</html>